Metal-working.



F. M. VOGEL.

METAL WORKING.

APPLICATION FILED AUG-10,1914.

1,1 96,498. PatentedAug. 29, 1916.

Witnesses:

Inventor:

Frederic M.Vo9el, ia. h's t. orney.

UNITED STATES PATENT OFFICE.

FREDERICK M. VOGEL, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL. ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METAL-WORKING.

Specification of Letters Patent.

Patented Aug. 29, 1916.

Application filed August 10, 1914. Serial No. 856,014.

To all whom it may concern Be it known that I, FREDERICK M. VOGEL, a citizen of the United States, residing at Pittsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Metal-WVorle ing, of which the following is a specification.

My invention relates to electric metal working, particularly to bending iron and steel angle bars, using that term in its broadest aspect as including the various I beams, channels, L shapes, T shapes, Z bars, etc.

The object of my invention is to provide an improved method for bending such bars.

My method of bending such bars consists in passing an electric current of considerable value through the flanges or other portions which must be stretched as the bars are bent, and substantially simultaneously therewith or immediately thereafter, bending the bars, the portions thereof heated by the passage of the current readily and uniformly stretching as required by the final form of the bar. The shape of the flange sections heated by the current may be varied considerably but in general the length of each part of the heated section, in the direction of the stretch should be proportional to the stretch required of that part of the section. Preferably the current is passed transversely through the flange or other portion of the bar but this is not essential. The apparatus I prefer to employ comprises electrodes for engaging opposite faces of the portions of the bars to be heated and a source of energy for passing current between the electrodes, the contacting faces of the electrodes being of such shapes and sizes that the current is passed through such sections of the bars as it is desired to heat.

More specifically my invention contemplates the bending of L shapes which I propose to do by passing current transversely to the bar through, and thereby heating, a triangular section of the flan e of the L shape, the apex of the triangular section being adjacent the web and the base be1ng on the external edge of the flange.

The single figure of the drawing illustrates the essential portions of a machine for bending L shapes, the source of electrical energy and its connections being illustrated diagrammatically.

the electrodes.

Such electrodes heat a considerable length of the external edge of the flange and but a short length of its base. The electrode 4: is stationary during the operation on any bar, but it may be adjusted when released by its grip bolt 6 for difi'erent sizes of bars, or it may be replaced by another electrode of another size for a different size of L- shape. The second electrode 5 is similar to the electrode 4;, but may be moved into and out of engagement with the flange 3 by the lever 7. Electrical energy is supplied to the electrodes 4 and 5 from the transformer 8, the two terminals of the secondary 9 of this transformer being connected to the two electrodes as illustrated. An adjustable reactance 10 controls the energy supplied to the primary 11 of the transformer 8, and hence the energy supplied to the angle iron; this regulating means is similar to that now in common use in electrical metal working machines.

The operation is as follows: The angle 1 is placed in position in its clamp 12 and bean ing against the electrode 4:. The electrode 5 is then brought into engagement with the flange 3 opposite the electrode 4 and current of considerable value passed between The value of this current is such that the flange 3 is heated over the triangular section between the electrodes to such a temperature that it may be readily stretched. After this section has become sufficiently heated, the left-hand end of the angle 1 may be bent downward by any suitable means, to the position 13 illustrated in dotted lines; the angle may be bent substantially simultaneously with the passage of current between the electrodes, or the circuit may be broken prior to the bending.

The triangular section is peculiarly adapted for bending L shapes, since the parts of the section are longest in the direction of the stretch where the greatest stretch occurs, that is adjacent the external edge of the flange, while those parts adjacent the Web and which are subject to little bending are of ineonsiderable length. The shapes and sizes of the sections will *ary considerably, however, with the form of the bend and the form of the angles operated on, as will be apparent.

While I have described the principle of my invention and the best mode I have contemplated for applying this principle, other modifications will occur to those skilled in this art and I aim in the appended claims to cover all modifications which do not involve a departure from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is 2- 1. The method of bending an angle iron through a web thereof which consists in passing current through flange portions thereof to be stretched to heat those portions without materially heating said web, and bending the iron while the flange portions are heated.

The method of bending angle irons which consists in passing current through sections of the portions to be stretched, thereby heating those sections, the lengths of the parts of the sections in the direction of the stretch being proportional to the stretch required of those parts, and bending the irons while those sections are heated.

3. The method of bending angle irons which consists in passing current trans- Yersely to the bar through sections of the portions to be stretched, thereby heating those sections, the lengths of the parts of the sections in the direction of the stretch being proportional to the stretch required of those parts, and bending the irons while those sections are heated.

4:- The method of bending an L shape which consists in; passing current trans- Yersely to the bar through, and thereby heating, a triangular section of the flange, the apex of the triangle being substantially adjacent the web and the base being substantially on the edge of the flange, and bending the bar at the web adjacent the apex of the triangular section while that section is heated.

In witness whereof, I have hereunto set my hand this 6th day of August, 19H.

FREDERICK U. VOGEL.

lVitnesses HENRY F. MILLER, C. I. INGRAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 01' Patents, Washington, D. G. 

